Effects of low- and high-LET radiation on the salt chemotaxis learning in

線虫の化学走性学習への低LET及び高LET放射線の影響

坂下 哲哉; 鈴木 芳代; 浜田 信行*; 下澤 容子; 深本 花菜*; 横田 裕一郎; 楚良 桜*; 柿崎 竹彦*; 和田 成一*; 舟山 知夫; 小林 泰彦

Sakashita, Tetsuya; Suzuki, Michiyo; Hamada, Nobuyuki*; Shimozawa, Yoko; Fukamoto, Kana*; Yokota, Yuichiro; Sora, Sakura*; Kakizaki, Takehiko*; Wada, Seiichi*; Funayama, Tomoo; Kobayashi, Yasuhiko

神経系のモデル生物として知られる線虫を用いて、化学走性学習に対する低LET及び高LET放射線の影響について調べた。また、野生型及び変異体の結果を比較した。高LET炭素線(C, 18.3MeV/u, LET=113keV/m)及びCo 線照射実験を行った結果、学習後期よりも初期の影響が大きい傾向及び変異体で応答が消失する点は両放射線で同じであった。以上の結果から、化学走性学習に関して低LET及び高LET放射線の両放射線とも影響を与えること、及びその作用メカニズムには遺伝子が関与していることが示唆された。

High linear energy transfer (LET) radiation is important cosmic rays that has neurobiological effects: it is known to induce conditioned taste aversion, and suppress neurogenesis that may underlie cognitive impairment. However, the impact of high-LET radiation on other learning effects remains largely unknown. Here, we focus on kinetics of the radiation response for the salt chemotaxis learning (SCL) behavior in the nameatode, , because the SCL during the learning conditioning was modulated after low-LET -irradiation. Firstly, the SCL ability was examined following high-LET irradiation (C, 18.3 MeV/u, LET = 113 keV/m), revealing its dose-dependent decrease after high- and low-LET exposure. Next, we demonstrate that the SCL at the early phase of the learning conditioning is greatly affected by high- and low-LET irradiation, and interestingly, the magnitude of these effects by high-LET radiation was smaller than that by low-LET one. Moreover, the analysis of mutant showed that the G-protein subunit, GPC-1 is responsible for such early phase response. This study is the first to provide the evidence for the kinetics of changes in SCL after high-LET irradiation of C. .